1. Field of the Invention
The present invention relates to a perpendicular magnetic write head provided with a magnetic pole layer that includes a magnetic pole tip portion of a narrow width defining a width of a write track and a yoke portion of a large width connected thereto.
2. Description of the Related Art
In recent years, performance improvement of a magnetic write head is required because of the increasing surface writing density of a magnetic recording medium such as a hard disk (hereinafter referred to as “recording medium”). Accordingly, a magnetic write head of a perpendicular magnetic write type (perpendicular magnetic write head) in which a signal magnetic field is set in a direction perpendicular to a recording surface of the recording medium attracts attention. This is because of advantages that a linear recording density becomes high and that the recorded recording medium is less affected by the influence of heat fluctuation.
The perpendicular magnetic write head is provided with a thin film coil for generating a magnetic flux, and a main pole layer which leads the magnetic flux generated in the thin film coil to the recording medium. This magnetic pole layer includes a tip portion (magnetic pole tip portion) of a narrow width that defines a width of a write track, and a rear portion (yoke portion) of a large width connected thereto.
Various studies have been conducted on configuration of the perpendicular magnetic write head to cope with further increasing recording density. Specifically, the magnetic pole tip portion is formed to include a high saturation flux density portion having a recess portion in the center thereof in a write track width direction, and a low saturation flux density portion embedded in the recess portion (Japanese Patent Application Publication No. 2006-139848). Besides, the magnetic pole layer is formed to include a lower layer having a high saturation flux density and an upper layer having a low saturation flux density (US Patent Application Publication No. 2004/0061973).